The tonsils and adenoids are generally located in the back of the human (mammalian) nose and throat, and are part of the lymphatic system that samples bacteria and viruses entering the body. Once sampled, the immune system is activated to produce antibodies that fight infection. When bacteria and viruses become trapped in the tonsils and adenoids, these tissues are able to break down their cell wall and deliver the fragments to areas of the body that produce antibodies modeled against the fragments. However, repeated inflammation of the tonsils and adenoids impedes their ability to destroy the bacteria that become entrapped therein, resulting in bacterial colonization of these tissues. The colonies of bacteria can then serve as a reservoir for repeated infections (e.g., tonsillitis or ear infections). Tonsillectomy and/or adenoidectomy may be indicated when antibiotic treatment fails to remove the bacterial reservoir. Tonsil tissue may also need to be removed if it enlarges to the point of causing airway obstruction, which may manifest as snoring or sleep apnea. Some individuals are also born with larger tonsils that are more prone to cause obstruction. Adenoidectomy may also be required to remove adenoid tissue when ear pain persists, or when nose breathing or function of the Eustachian tubes is impaired.
The devices and techniques used for tonsillectomy and adenoidectomy will usually depend on such factors as the type and amount of tissue to be removed and surgeon preference. The two procedures are routinely performed together. A common method for tonsillectomy and adenoidectomy employs cold surgical dissection. Here tissue is removed using a scalpel or other sharp instrument such as a curette or punch device. Sharp dissection oftentimes results in heavy bleeding, which can be stemmed with electrocautery.
In addition to coagulation, electrosurgery devices (e.g., suction-tipped, blade, or needle tip Bovies) may also be employed to resect tonsil or adenoid tissue. The suction tipped Bovie typically has a hollow center to suction blood, secretions, and smoke from the surgical field, and a rim of metal for cutting and coagulation. A separate aspirator is used when blade and needle tip Bovies are used. Although the use of Bovies reduces blood loss intraoperatively in comparison to cold techniques, it is associated with increased postoperative pain due to spread of the thermal injury from the heat of electrosurgery (average temperatures are above 300° C.). Despite their increased thermal injury profile, use of the Bovie remains the most popular method of tonsil removal in the U.S. due to its speed, convenience, universal availability, and surgeon familiarity with the device.
Other energy-type devices have been commercialized that attempt to minimize thermal injury. These include the Harmonic Scalpel® system (Ethicon Endo-Surgery, Cincinnati, Ohio) (ultrasonic energy), lasers (e.g., KTP, Nd:YAG, or CO2 lasers), and Coblation® devices (Arthrocare, Austin, Tex.) (bipolar radiofrequency ablation). However, the decrease in thermal injury provided by these devices is questionable. Even if they do result in less thermal injury, it is offset by reduced control of bleeding and surrounding tissue trauma, longer operative times, or less precise cutting. Some of the instruments also obscure the surgical field and are difficult to maneuver due to their large size.
When Coblation® devices are employed, the procedure requires saline delivery in order to establish an electrosurgical effect. Pre-operative time is prolonged due to the inclusion of the saline delivery set-up. Coblation® device aspiration lumens also periodically clog during the procedure, which causes saline to pool in the patient's throat. The pooled saline must then be suctioned using a separate aspirator. Additionally, the Coblation® device lumen typically has to be manually cleared in order to finish the surgery.
Accordingly, new devices for resecting tonsil and adenoid tissue would be useful. In particular, devices that precisely cut tonsil and adenoid tissue while effectively controlling bleeding and surrounding tissue trauma would be desirable. Devices that provide easier access to the tonsils and adenoids and manipulation of those tissues would also be desirable.